Traffic signal



April 9, 1929. T. w. ROLPH 1,703,108

TRAFFIQSQIGNAL Filed Dec. 11, 1926 25 o lv I O A. I G 22 ,4- I 3 I 0 INVENTOR Thomas Hf Hozjnh ATTORNEY Patented Apr. 9, 1929.

UNITED STATES 1,708,108 PATENT OFFICE.

THOMAS W. ROLPILYOF NEWARK, OHIO, ASSIGNOR TO HOLOPI-IANE COMPANY, INC, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TRAFFIC SIGNAL.

Application filed December 11, 1928. Serial No. 154,299.

The present invention relates to traflic signals and is more particularly directed toward a trafiic signal having a single light source and provided with suitable stationary and moving parts arranged for giving traffic signals.

The traflic signal contemplated by the present invention may utilize any suitable single source, as a lamp or a burner. This light source is surrounded by a refractor preferably made of glass which concentrates the light in a horizontal plane. This horizontal concentration may be modified. at any moderate angle above or below the horizontal. This modification is accon'iplished by moving the light center to a proper distance above the focus when concentration is desired at a given angle below the horizontal; or, by moving the light center a proper distance below the focus when concentration is desired at a given angle above the horizontal. Since these angles above or below the horizontal are not large for the ordinary requirements of such a signal, the general horizontal direction has been designated herein as lateral.

While the refractor may be in the form of a preferably stationary cylindrical Fresnel lens, it is preferable, where the traffic signal is being used on an ordinary four-way street corner, to use a refractor which produces the desired number of light beams, usually four, arranged at right angles to one another. here a stationary refractor is used, the color of the light emitted from the signal in each of the four directions may be changed from red to yellow and to green and vice versa by a simple movement of a screen carrying a frame which either revolves outside the refractor or which moves back and forth as desired.

In one form of the invention we find three elements, namely a stationary .refractor, a movable set of color screens and a distributing roundel or cover glass, these three elements being in the order named from the lamp.

The invention also preferably contemplates the use of a stationary structure placed outside the colored screens and arranged to prevent the escape of stray light in undesired directions and also provided with cover lasses or roundels adapted to spread the light horizontally and down.- wardly onto the road or pavement.

Other and further objects of the invention will appear as the description proceeds.

The accompanying drawings show, for purposes of illustrating the invention, one of line many possible embodiments in which it may take form, it being understood that the drawings are illustrative of the invention rather than limiting the same.

In these drawings:

Fig. 1 is a vertical sectional view through a tratlic signal adapted for use at the inter? section of four streets.

Fig. 2 is a horizontal sectional view through the traffic signal, the portion of the figure to the left of the center line being viewed in a downward direction and the portion to the right of the center line being viewed in an upward direction;

Fig. 3 is an elevational view of a complete traffic signal; and Figure 4 is an enlarged sectional view of the refractor, with part in elevation, and taken in the same direc ion as Figure 1.

As shown in the drawings, the light source is indicated at 10 in the form of an electric lamp supported from a socket 11 which is attached to an H-shaped member 12 supported in the manner to be described. A retracting means 13, here shown in the form of a glass refractor made in one or four pieces and adapted to concentrate or direct light in four directions, at right angles to each other, is supported underneath the H- shaped member 12 so that the filament of the lamp is mounted at or slightly above or below the focus of the refraetor or refracting means. However, in some cases, instead of using such a refractor, a cylindrical Fresnel lens, which sends out a lateral sheet of light is used. A convenient method of supporting the refractor is to provide it with a number of lugs 14 to cooperate with bolts 15 carried by the frame 12.

The ends 16, 17, 18 and 19 of the H-shaped lamp supporting member are mounted on stationary framework 20 carried on the upper part of the traffic signal. As there shown this framework includes eight equally spaced vertical members 21. These vertical members carry four roundels or cover glasses 22, 23, 24 and 25. The framework also carries opaque plates 26 placed between the cover glasses so as to cut off stray light and provide a closure for the signal. This framework 20 be carried on the upper end of a pedestal 27 so to locate the traflic signal at the desired height above the street.

The refractor 13 acts on the light to produce the plurality of laterally directedhor-izontal beams wherein the rays ineach beam are substantially parallel with one another. The color of this light may be changed by passing it through suitable colored screens interposed in the path ofthe light emittedby the refractor. As the light rays in a beam are parallel they pass through the screen without change of direction or appreciable diffusion or scattering.

In order that the color of the light emitted from the signal may be varied, there is here provided a rotatable screen frame 28 which supports a number of colored" screens. As here shown, these screens include two green screens and two red screens, arranged in pairs opposite one another and yellow screens between each red and green screen, the color of the screens being designated by the letters G, R and Y, respectively. This screen frame is mounted on a shaft 29 which may be actuated by any convenient means to rotate or. oscillate it. Suitable means to so actuate it are here showninthe form of a pair of bevel gears 30 and 31. The first gear being mounted on the frame 28 and the second being supported by the pedestal. A handle 32 may be used to operate the first bevel gear to move the screen-frame.

hen the signal is mounted above eye level the center of'the lamp or light source 10 is preferably placed aslight distance above the focus of the rcfractingmeans so that the main beam of light emitted by the roundels will be bent slightly downward toward the pavement so as to be more easily visible by drivers. The ronndels are preferably designed so that the light willbe spread laterally somewhat as indicated at the left of Fig. 2.

It will. be noted that the present traffic signal utilizesa single light source which, ashore shown, may be mounted stationary. The refractors are mounted around the light source so that the light is concentrated in the lateral beams which may be directed along the center ofthe intersecting streets. \Vhen the color screens are set up asindicatcd' in the drawings, one street will receivethe green indication for traiiic to pass through, while the cross street willreceive the redindication for stopping traflic. As the screenismoved a quarter turn in either direction, or rotated in steps of 90 the light is changed from green or red through yellow tored or green as the case may be, thereby giving the caution signal between the red and green signals in each case.

lVhile the construction shown in the'present drawings is devised for street intersections at right angles and'for giving a cantion signalbetween the red and green signal, it will of course be understood that the optical parts may be arranged to give the sig nals for any number of streets and also where the intersections are not at right angles, and the caution signal may also be omitted if desired. In case the caution signal is omitted, the refractor and color screens maybe mounted on the same frame so as to move as a unit.

It is obvious that the invention may be embodied in many forms and constructions, and 1 wish it to be understood that the particular form shown is one of the many forms. Various modifications and changes being possible, I do not limit myself in any way with respect thereto.

1 claim:

1. A traffic signal comprising a centrally disposed lightsource, retracting means about the light source for concentrating the light into lateral beams, a screen frame mounted to be movable about a vertical axis, colored screens carried thereon outside the refracting means, stationary cover glasses outside the colored screens, opaque members between the cover glasses the parts cooperating to emit light in the form of lateralbeams of colors determined by the position of the screen frame.

2. A traflic signal comprising a centrally disposed light source, retracting means about thelight sourcefor concentrating the light into lateral beams, a screen frame mounted tobe movable about a vertical axis, colored screens carried thereon ou-tsidetherefractingmeans, stationary cover glasses outside the colored screens, opaque members between the cover glasses the parts cooperating to emit light in the form of lateral beams of'colors determined by the position of the screen frame, the center ofthe light source being above-the focus of the rcfraeting means so that the light spread dowilvntrdlyi 3. A traiiic signal comprising a centrally disposed light source,stationarymeans surrounding the light source for redirecting the light into a plurality of lateral beams, a movable screen frame, colored screens carried thereon outside the re-directing means, and means to'move the screen frame to present different screens across the light beams.

4. A trathc signal comprising a centrally disposed light source, refracting means surrounding the light source for redirecting the light into a plurality of'l'ateral beams, a movable sc-reen frame, colored. screens carried thereon outside the refracting means, means to move the screen frame to present different screens across the light beams, and stationary light spreading cover glasses carried outside the colored screens and interposed inthe light beams. V

5. A trafiic signal comprising a centrally disposed light source, retracting means surrounding the light source for redirecting the light into a-plurality of lateral beams, a movable screen frame, colored screens carried thereon outside the retracting means, means to move the screen frame to present different screens across the light beams, stationary light spreading cover glasses carried outside the colored screens and interposed in the light beams, and opaque members between the cover glasses to prevent the escape of stray light.

(5. A traflie signal comprising a centrally disposed light source, refracting means surrounding the light source for redirecting the light into a plurality of lateral beams, a movable screen frame, colored screens carried thereon outside the refracting means, means to move the screen frame to present different screens across the light beams, and statimiary cover glasses carried outside the colored screens andinterposed in the light beams, the cover glasses being adapted to spread the light horizontally and direct it downwardly onto the road.

7. A traffic signal comprising a centrally disposed light source, retracting means sur rounding the light source, for redirecting the light into a plurality of lateral beams, a movable screen frame, colored screens carried thereon outside the refracting means, means to move the screen frame to present different screens across the light beams, stationary light spreading cover glasses carried outside the colored screens and interposed in the light beams, and stationary baflies at each side of the cover glasses.

8. A trafiic signal comprising a centrally disposed light source, refracting means surrounding the light source, for redirecting the light into a plurality of lateral beams, a movable screen frame, colored screens carried thereon outside the retracting means, means to move the screen frame to present different screens across the light beams, and stationary light spreading cover glasses carried outside the colored screens and interposed in the light beams, the center of the light source being above the focus of the refracting means so that the light is sent downwardly.

9. A traflic signal comprising a centrally disposed light source, a stationary refractorsurrounding the light source, for redirecting the light into four lateral beams at right angles to one another, a movable screen frame, two red screens and two green screens carried thereon outside the refractor and placed opposite one another in pairs and means to move the screen frame to present different screens across the light beams so that a red light beam is sent in one direction and a green light beam is sent in the other direction.

10. In. a tra'liic signal, a light source, a refracting device adapted to concentrate the light into a plurality of horizontal beams with the rays therein substantially parallel, movable color screens adapted to modify the color of the light beams without changing the direction of the rays thereof, and a light transmitting and distributing member beyond the screens and adapted to redistribute the parallel light rays in desired directions.

11. In a traliic signal, a light source, a refracting device adapted to concentrate the light into four horizontal beams with the rays in each beam substantially parallel, movable color screens adapted to modify the color of the light beams without changing the direction of the rays thereof, and a light transmitting and distributing member beyond the screens and adapted to redistribute the parallel light rays in desired directions.

12. In a tratlic signal, a light source, a retracting device adapted to concentrate the light into a plurality of horizontal beams with the rays therein substantially parallel, movable color screens adapted to modify the color of the light beams without changing the direction of the rays thereof, and a light transmitting and distributing member beyond the screens, said member having refracting elements for bending the parallel light rays downwardly.

13. In a traliic signal, alight sonree, arrefracting device adapted to concentrate the light into a plurality of horizontal beams with the rays therein si'lbstantially parallel, movable color screens adapted to modify the color of the light beams without changing the direction of the rays thereof, and a light transmitting and distributing member beyond the screens, said member l'iavii'ig retracting elements for causing the light rays in each beam to diverge horizontally.

Signed at New York, in the county of New York and State of New York, this 9th day of December, 1926.

THOMAS lV. ROLPH. 

